The former chief of staff to Secretary of State Colin Powell pledged Tuesday to testify against former Vice President Dick Cheney if he is ever tried for war crimes.

Col. Lawrence Wilkerson told Democracy Now's Amy Goodman that he would participate in a trial even if it meant personal repercussions.

"I, unfortunately — and I've admitted to this a number of times, publicly and privately — was the person who put together Colin Powell's presentation at the United Nations Security Council on 5 February, 2003," Wilkerson said. "It was probably the biggest mistake of my life. I regret it to this day. I regret not having resigned over it."

In an interview that aired on NBC Monday, Cheney told Jamie Gangel that unlike President George W. Bush, he did not have a "sickening feeling" when they discovered there were no weapons of mass destruction after the invasion of Iraq.

"I think we did the right thing," Cheney said.

Joining Wilkerson and Goodman to discuss Cheney's new book "In My Time," Salon's Glenn Greenwald said that it was disturbing to see the former vice president treated simply as an "elder statesman."

"The evidence is overwhelming… that Dick Cheney is not just a political figure with controversial views, but is an actual criminal, that he was centrally involved in a whole variety not just of war crimes in Iraq, but of domestic crimes, as well, including the authorization of warrantless eavesdropping on American citizens in violation of FISA, which says that you go to jail for five years for each offense, as well as the authorization and implementation of a worldwide torture regime that, according to General Barry McCaffrey, resulted in the murder — his word — of dozens of detainees, far beyond just the three or four cases of waterboarding that media figures typically ask Cheney about," Greenwald explained.